There is a difference between looking good by accident and walking in like every detail already passed inspection. The dress sits right, the jacket falls open at exactly the wrong-right angle, and nothing about it feels random.
The real signal is not how much skin is showing. It is the calm around it. She is not asking the group if it is too much, because she already knows what the mirror told her.
Next comes the part that makes the attention harder to brush off: how she handles praise when it finally arrives.